Thinking back over the times I've been involved in serious wrist grabbing I was wondering if aikido folks are really ready to have someone grab their wrists with serious intent.

The few times I've seen wrists grabbed in ernest the main idea was to block a punch, stop the attacker from hitting someone and then use the wrist grab to hurt the attacker, swinging the attacker into railings, walls, stairs, other attackers or moving into some sort of lock.

Notice that the attacker is the one being grabbed and the person grabbing is the one throwing or locking. That's just a bit different from what I've seen practiced at the dozen or so dojos I've hung around at. It is common however in places I've trained at that nage is the aggressor. It's just that defenders in real life, my personal experience, are a lot more proactive about doing something than aikido ukes,

I think the joke about what we can do to someone that grabs a wrist is really just a joke. Try something and most people will just let go.
Someone that come out of the blue grabs your arm and swings you into a wall. I haven't seen anything like that trained for.